Saturday, September 1, 2012

Irrigated corn yield potential is predicted to be 2-8% below long-term average, while dryland yield potential in much of the Corn Belt will be moderately to severely reduced, falling 22-67% below normal.

To forecast potential production at 12 sites across the Corn Belt University of Nebraska–Lincoln crop experts used a "Hybrid-Maize model" to estimate end-of-season yield potential based on actual weather up to August 27, and historical long-term weather data to complete the season using data from each of the past 30 years.

Simulations were run for dryland corn in Iowa, Illinois, and South Dakota, and for both irrigated and dryland corn in Nebraska. Simulations were based on the typical planting date, hybrid relative maturity, plant population, and soil properties at each location.

The bottom line is that 2012 irrigated yields will be moderately lower than the long-term averages (2-8% below normal), while dryland corn yield potential in much of the Corn Belt will be moderately to severely reduced (22-67% below normal).

It is important to keep in mind that yields can be even lower at places where both prolonged drought and high temperature stress at pollination have occurred. Also, greater field-scale variability is being observed this year in irrigated fields due to the inability of some irrigation systems to keep up with crop water use demand, problems with pivot irrigation nozzles and uneven watering, and additional stresses from insects and diseases. Such problems can contribute to reduced yields at irrigated sites of more than the 2-8% simulated by the model.